Cap



R. H. AMEN 3,129,808

April 21, 1964 CAP Filed May 5, 1961 INV EN TOR.

1205527 AMEN ATTOEIVEKS United States Patent 3,129,808 can Robert H.Amen, Fremont, Calif, assignor, by rnesne assignments, to Barnes-findinternational, Inc, a corporation of (Ialifornia Filed May 3, 1961, Ser.No. 107,545 ll Claim. (Cl. 206-) This invention relates to a cap andmore particularly relates to a leak-proof cap suitable for use on acontact lens case or the like.

One of the most useful contact lens cases is one wherein a pair ofopposed pistons is provided within a cylinder housing, said pistonsbeing held apart by a spring action and wherein each of the pistons hasa concave receptacle for a single contact lens; the body of thecylindrical member serves as a receptacle for a liquid in which the lensis kept immersed. Such cases are ordinarily made of a soft plastic andsufier from the defect that there is a pumping action, as is hereinafterexplained in more detail, so that each time a cap is put on the case,one or more drops of liquid is squeezed to the outside of the case.

It is therefore an object of the present invention to provide a cap fora contact lens case which will not have a pumping action.

Another object of this invention is to provide a cap for a contact lenscase of generally improved design.

Other features and advantages of the present invention will be broughtout in the specification which follows.

In the drawings forming part of this application:

FIGURE 1 is a partial sectional view of a contact lens case showing acap embodying the present invention.

FIGURE 2 is an enlarged bottom plan view of a cap embodying the presentinvention.

FIGURE 3 is a section on the line 33 of FIGURE 2.

Referring now to the drawings by reference characters, there is shown inFIGURE 1 a partial sectional view of a typical contact lens cases. Sucha case is fully described in the co-pending patent application of FrankE. Brown, Serial No. 810,708 filed May 4, 1959, now Patent 3,- 070,105.Such a case has a central barrel-like housing 4 having a cylindricalinner wall 6 terminating in an inturned lip 8. A piston 10 is free toslide within the cylindrical wall 6 and is urged outwardly by a spring12. The outside of the housing is threaded at each end as at 14 and acap 16 having mating threads 17 closes the normally open end. The piston10 has a concave head 18 on which a contact lens can rest while the center of the piston is open as at 20 so that the space 22 above the pistonis in fluid connnunication with the open center 24 of the housing 4-.The cap 16 has an annular skirt 26 near its periphery which serves topress down on the piston 10 as the cap is applied. In addition, the caphas a ribbed structure as at 28 which serves to prevent a lens fromsticking to the cap. Of course, the rib structure 28 can be made invarious forms and forms no part of the present invention.

In using such cases the cap is removed whereupon the piston will rise inthe cylinder 6 until it is retained upon the lip 8. When in thisposition, the concave surface 18 will be at the open end of the case andit is easy to place a contact lens on the concave surface. The cap isthen applied and the annular skirt 26 will press the piston downward asit is screwed into place so that the lens will become immersed in theliquid which is normally contained in the open center 24. Of course, asthe cap is removed, the piston will rise so that it will be easy toremove the lens from the case after the cap has been taken 01f. InFIGURE 1 this general structure has been illus- Patented Apr. 21, 1964trated, it being understood, of course, that normally the case would bebuilt with two ends, the other and being merely a mirror image of theportion illustrated.

As heretofore constructed, the caps for such cases have had a solidannular skirt 26. Since there will normally be at least a few drops ofliquid retained on the top of the piston as it raises out of the liquid,some liquid will be trapped in the space 30 between the skirt 26 and theinner surface 6 of the housing. As one then continues to screw on thecap, the space 30 will be come reduced in volume and, since there is atight seal between the skirt 2d and the top of the piston 10, thisliquid will be forced through the threads and will find its way to theoutside of the case. Since such cases are ordinarily used oversubstantial periods of time without filling the open central portion 24,it is apparent that the loss of a drop or two of liquid upon eachclosing will cause the liquid to become soon exhausted. Further, it isalways inconvenient to have a wet article to place in the pocket orpurse.

In accordance with the present invention this difiiculty is solved byproviding at least one slot 32 in the annular skirt. A second opening34- may be provided if desired and an even greater number of slots maybe used in the annular skirt. However, more than two slots have not beenfound necessary since these two slots provide sufficient relief for theentrapped liquid. It is apparent that as the cap is screwed down, theliquid and air which would normally be trapped in the space 30 can nowflow through the slots 32 and 34- so that the liquid is no longer exudedfrom the case.

It is believed apparent from the foregoing that I have provided a capfor a contact lens case of improved design and one which does not exudeliquid from the case as it is applied to the case.

I claim:

In a contact lens case wherein said case has a tubular structure with anexternally threaded end with a movable piston mounted within saidtubular structure, said piston having a concave portion adapted toreceive a contact lens and a rim at the edge of said concave portion,said tubular structure having an inturned lip which bears against aportion of said rim to prevent the piston from coming out of the tubularstructure, the improvement comprising a single piece cap having a roundend portion, a first downturned annular skirt at the periphery of theend portion, said first skirt having internal threads thereon adapted tomate with the external threads of the tubular structure and a secondannular skirt of smaller diameter than the first skirt and concentrictherewith, said skirt extending downwardly from said end portion andhaving a length slightly shorter than the first skirt, said second skirtbeing adapted to press against the rim of the piston and depress thesame, and a passage in the second skirt, said passage linking theannular area formed between the first and second skirts and the internalcircular area defined by the second skirt whereby liquid can passthrough said passage while said second skirt is in contact with saidrim.

References Cited in the file of this patent UNITED STATES PATENTS1,413,907 Gerstenberger Apr. 25, 1922 2,049,977 Ross Aug. 4, 19362,175,993 Lighton Oct. 10, 1939 2,297,326 Rieser Sept 29, 1942 2,620,938Jesnig Dec. 9, 1952 2,990,079 Garvey June 27, 1961 3,010,596 WilliamsNOV. 28, 1961 3,070,105 Brown Dec. 2 1962

